A tapping device for machining cast parts

Abstract

The present application relates to the field of valve stem tapping, in particular to a thread tapping device for casting part machining, which comprises a base, a hydraulic cylinder and a chuck, the hydraulic cylinder is horizontally installed at the top end of the left side wall of the base, the chuck is installed at the output end of the hydraulic cylinder, the chuck locks the valve stem, the hydraulic cylinder drives the chuck to move horizontally, so that the valve stem reaches the machining point, a tapping mechanism is installed on the upper surface of the right side of the base, a durability detection mechanism is installed at the output end of the tapping mechanism, a chuck is installed at the left end of the durability detection mechanism, the chuck locks a tap, and the tap is driven by the tapping mechanism to move spirally left and right. The present application completely replaces the conventional electric control tapping mode of frequent forward and reverse rotation of the motor, avoids high temperature loss of the motor due to frequent commutation from the root, significantly prolongs the service life of the motor, completely eliminates the failure hidden dangers such as poor heat dissipation of the electric control system, line short circuit and signal misoperation, eliminates the risk of tapping misoperation, and effectively improves the machining qualified rate of the valve stem internal thread and the production safety.

Description

Technical Field

[0001] This invention relates to the field of valve stem tapping technology, specifically a thread tapping device for machining castings. Background Technology

[0002] Castings are fundamental components in mechanical equipment, valve and pump bodies, and construction machinery. To meet assembly and connection requirements, most castings require internal threads to be formed at the ends or inside cavities through tapping. Due to the diverse materials of castings (cast iron, cast steel, cast aluminum, etc.), uneven hardness of some workpieces, and the presence of an oxide layer on the surface, the cutting load for thread tapping fluctuates greatly, placing high demands on the stability of the machining equipment.

[0003] Currently, internal thread machining of castings commonly uses electrically controlled tapping equipment, where an electrical control system drives a tap motor to perform a cyclical action of forward tapping and reverse retraction. In continuous batch production, the motor needs to frequently operate in both directions, which easily leads to overheating. This not only accelerates motor wear and shortens its service life but also poses a risk of electrical control failure. Furthermore, factors such as workshop dust, vibration, poor heat dissipation, short circuits, and signal interference can cause the electrical control system to malfunction or misoperate, resulting in abnormal tapping processes, damage to castings, and reduced yield.

[0004] Furthermore, the tapping process for castings is complex, with high cutting loads and rapid wear rates, resulting in significant fluctuations in the effective service life of the taps. Existing tapping equipment lacks a tap condition monitoring mechanism, making it impossible to detect the sharpness and durability of the taps in real time. When the taps become worn and dull, there is no timely warning or replacement, which directly leads to reduced internal thread machining accuracy, tooth profile defects, and tooth decay, seriously affecting the machining quality and assembly reliability of castings. Summary of the Invention

[0005] The purpose of this invention is to provide a thread tapping device for machining castings, in order to solve the problems mentioned in the background art, such as high equipment wear and tear, safety hazards, inability to monitor and replace taps in a timely manner, and unstable quality of thread machining in castings.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a thread tapping device for machining castings, comprising a base, a hydraulic cylinder, and a chuck. The hydraulic cylinder is horizontally mounted on the top of the left side wall of the base, and the chuck is mounted on the output end of the hydraulic cylinder. The chuck locks the casting to be machined, and the hydraulic cylinder drives the chuck to move horizontally, allowing the casting to reach the machining point. A tapping mechanism is mounted on the upper right surface of the base, and a durability testing mechanism is mounted on the output end of the tapping mechanism. A chuck is mounted on the left end of the durability testing mechanism, and a tap is locked in the chuck. The tapping mechanism drives the tap to move left and right in a spiral motion to tap the casting, while the durability testing mechanism tests the working state of the tap during tapping. An alarm electrically connected to the durability testing mechanism is mounted on the upper surface of the tapping mechanism.

[0007] Preferably, the tapping mechanism includes a housing mounted on the upper right surface of the base. A drive assembly and a conveying assembly are respectively installed at the upper and lower ends of the housing's inner cavity. The drive assembly controls the operation of the conveying assembly. A first screw is screwed to the top of the left side wall of the housing. A first gear, meshing with the conveying assembly, is installed at the right end of the first screw. The conveying assembly drives the first screw to rotate in both directions, causing it to move left and right in a spiral motion, thus performing the tapping action. The drive assembly provides power to the conveying assembly, allowing the first screw to rotate and reciprocate left and right, providing a tapping path.

[0008] Preferably, the conveying assembly includes a first splined shaft and a second screw, which are respectively mounted on the upper and lower ends of the right inner wall of the housing via bearings. The right ends of both the first splined shaft and the second screw are equipped with meshing second gears. The first splined shaft and the second screw rotate synchronously via the transmission of the two second gears. One end of the second screw is screwed to the outer wall of the second screw, and the other end of the movable seat is sleeved on the outer wall of the first splined shaft. When the second screw rotates clockwise or counterclockwise, the rotational force of the second screw thread can drive the movable seat to move to the left or right. A third gear, meshing with the first gear, is installed on the top of the left side wall of the movable seat. The third gear is driven to rotate by the first splined shaft; it not only drives the first screw to rotate but also moves synchronously with the first screw.

[0009] Preferably, the first screw and the second screw have the same thread direction.

[0010] Preferably, the drive assembly includes a frame installed in the upper right corner of the housing cavity, a guide rod installed at the bottom inner side of the frame, a rack slidably connected to the outer wall of the guide rod and meshing with the second gear, a pin installed in the middle of the upper surface of the rack, and a rotating unit installed at the top inner side of the frame. The rack is driven to move back and forth by the rotating unit cooperating with the pin. The purpose is to replace the electric motor control method with mechanical reciprocating motion, avoid electric control errors, and prevent the occurrence of safety hazards.

[0011] Preferably, the rotating unit includes a motor mounted on the front of the frame, with one end of a rotating drum mounted on the output end of the motor, and the other end of the rotating drum connected to the inner wall of the frame via a bearing. The outer wall of the rotating drum has a sliding groove, and a pin is inserted into the inner cavity of the sliding groove.

[0012] Preferably, the grooves are elliptical in shape and distributed on the outer wall of the rotating drum.

[0013] Preferably, the durability testing mechanism includes a piston cylinder installed at the left end of the first screw. The inner cavity of the piston cylinder is filled with hydraulic oil. A second spline shaft and a piston are sequentially inserted into the piston cylinder from left to right. The second spline shaft is fixedly connected to the piston. The left end of the second spline shaft is installed at the right end of the chuck. The piston withstands the pressure changes during tapping. A testing component is installed on the outer wall of the piston cylinder. The pressure borne by the tap during tapping is converted into hydraulic oil pressure, and the hydraulic oil pressure is converted into mechanical power for the testing component.

[0014] Preferably, the detection assembly includes a housing mounted on the outer wall of the piston cylinder. A through hole is provided at the bottom front of the housing. A Bourdon tube is installed on the outer wall of the piston cylinder, and the Bourdon tube is located within the inner cavity of the housing. The Bourdon tube is arc-shaped and elastic; as the hydraulic oil pressure gradually increases, the curvature of the Bourdon tube decreases. A connecting rod is mounted at the top of the Bourdon tube via a pin. A rocker arm is mounted on the front side of the inner cavity of the housing via a pin, and the top of the rocker arm is connected to the other end of the connecting rod via a pin. An adjustment unit is installed at the bottom front of the housing. The adjustment unit is triggered by the rocker arm's swing to monitor the tap's durability.

[0015] Preferably, the connection between the swing arm and the box body is located at the top of the swing arm.

[0016] Preferably, the adjustment unit includes a slide bar installed at the bottom of the front of the box, a slide seat slidably connected to the outer wall of the slide bar, a positioning bolt screwed onto the lower surface of the slide seat, and fixing the slide seat to the outer wall of the slide bar when the positioning bolt is turned into contact with the slide bar. A proximity switch electrically connected to the alarm is installed on the upper surface of the slide seat.

[0017] Compared with the prior art, the beneficial effects of the embodiments of the present invention are: 1. This invention employs a motor-driven rotary drum, which, through the engagement of a sliding groove and a pin, achieves the linear reciprocating motion of a rack. A second gear then drives the first splined shaft and the second screw to rotate synchronously. The second screw drives the moving seat to move left and right, and a third gear meshes with the first gear, causing the first screw to drive the tap in a rotary axial movement, completing the tapping and retraction actions. This completely replaces the traditional electrically controlled tapping method with frequent forward and reverse rotation of the motor, fundamentally avoiding the high-temperature losses caused by frequent motor reversals, significantly extending the motor's service life. Simultaneously, it completely eliminates potential failures such as poor heat dissipation, short circuits, and signal malfunctions in the electrical control system, eliminating the risk of tapping errors. It is suitable for batch continuous processing of castings, effectively improving the thread processing qualification rate and production safety of castings.

[0018] 2. This invention transmits the tapping resistance of the tap to the piston through the second spline shaft, squeezing the hydraulic oil inside the piston cylinder to generate pressure changes. The hydraulic pressure drives the Bourdon tube to deform, and then the deformation is converted into mechanical oscillation through the linkage and rocker arm. When the rocker arm triggers the proximity switch, the alarm sounds immediately, realizing real-time online monitoring of the tap's durability and sharpness. In view of the characteristics of uneven material hardness and large fluctuations in cutting load of castings, it can provide early warning and replacement when the tap becomes worn and dull, avoiding problems such as thread defects, tooth decay, and reduced machining accuracy caused by tap dulling, thus ensuring the stable machining quality of castings.

[0019] 3. This invention allows for flexible adjustment of the proximity switch trigger position by sliding the slide block on the slide bar, and precise setting of the tap durability monitoring threshold. It can adapt to the tapping and monitoring needs of castings of different materials and hardnesses, such as cast iron, cast steel, and cast aluminum, greatly improving the versatility and adaptability of the device to different working conditions, and meeting the requirements of diversified batch production. Attached Figure Description

[0020] Figure 1 This is a perspective view of the present invention; Figure 2 This is a perspective view of the tapping mechanism of the present invention; Figure 3 This is a perspective view of the conveying component of the present invention; Figure 4 This is a left view of the driving component of the present invention; Figure 5 This is a left view of the rotating unit of the present invention; Figure 6 This is a perspective view of the durability testing mechanism of the present invention; Figure 7 This is a perspective view of the detection component of the present invention; Figure 8 This is a perspective view of the adjustment unit of the present invention.

[0021] In the diagram: 1. Base; 2. Hydraulic cylinder; 3. Chuck; 4. Tapping mechanism; 5. Durability testing mechanism; 6. Chuck; 7. Tap; 8. Alarm; 41. Housing; 42. Conveying assembly; 43. Drive assembly; 44. First screw; 45. First gear; 421. First splined shaft; 422. Second screw; 423. Second gear; 424. Moving seat; 425. Third gear; 431. Frame; 432. Guide rod; 433. Rack; 4 34. Pin; 435. Rotating unit; 4351. Motor; 4352. Rotary drum; 4353. Slide groove; 51. Piston cylinder; 52. Hydraulic oil; 53. Piston; 54. Second spline shaft; 55. Detection assembly; 551. Box; 552. Through hole; 553. Bourdon tube; 554. Connecting rod; 555. Rocker arm; 556. Adjustment unit; 5561. Slide bar; 5562. Slide block; 5563. Positioning bolt; 5564. Proximity switch. Detailed Implementation

[0022] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0023] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0024] Please see Figures 1-8 In this embodiment of the invention, a thread tapping device for processing castings includes a base 1, a hydraulic cylinder 2, and a chuck 3. The hydraulic cylinder 2 is horizontally mounted on the top of the left side wall of the base 1. The chuck 3 is mounted on the output end of the hydraulic cylinder 2 and is a three-jaw chuck. The chuck 3 locks the casting to be processed. The hydraulic cylinder 2 drives the chuck 3 to move horizontally, allowing the casting to reach the processing point. A tapping mechanism 4 is mounted on the upper right surface of the base 1. A durability testing mechanism 5 is mounted on the output end of the tapping mechanism 4. A chuck 6 is mounted on the left end of the durability testing mechanism 5. A tap 7 is locked in the chuck 6. The tapping mechanism 4 drives the tap 7 to move left and right in a spiral motion to tap the casting. The durability testing mechanism 5 tests the working state of the tap 7 during tapping. An alarm 8 electrically connected to the durability testing mechanism 5 is mounted on the upper surface of the tapping mechanism 4. When the alarm 8 sounds, it reminds that the tap 7 has reached the wear threshold and needs to be replaced in time.

[0025] Furthermore, the tapping mechanism 4 includes a housing 41 installed on the upper right side surface of the base 1. The upper and lower ends of the housing 41 are respectively provided with a drive assembly 43 and a conveying assembly 42. The drive assembly 43 controls the operation of the conveying assembly 42. A first screw 44 is screwed to the top of the left side wall of the housing 41. A first gear 45 that meshes with the conveying assembly 42 is installed on the right end of the first screw 44. The conveying assembly 42 drives the first screw 44 to rotate back and forth, so that the first screw 44 moves left and right in a spiral motion to perform the tapping action of the tap 7.

[0026] Furthermore, the conveying assembly 42 includes a first splined shaft 421 and a second screw 422 respectively mounted on the upper and lower ends of the right inner wall of the housing 41 via bearings. Both the first splined shaft 421 and the second screw 422 have meshing second gears 423 mounted on their right ends. The first splined shaft 421 and the second screw 422 rotate synchronously via the two second gears 423. The threads of the first screw 44 and the second screw 422 are in the same direction. When the rotational force of the second screw 422 drives the moving seat 424 to move, the first gear 45 can engage with the third gear. 425 is always in a meshed state. One end of the movable seat 424 is screwed to the outer wall of the second screw 422. The other end of the movable seat 424 is sleeved on the outer wall of the first spline shaft 421. When the second screw 422 rotates clockwise or counterclockwise, the rotational force of the screw thread can drive the movable seat 424 to move to the left or right. A third gear 425 is installed on the top of the left side wall of the movable seat 424 and meshes with the first gear 45. The third gear 425 is driven to rotate by the first spline shaft 421, which does not affect the left and right movement of the third gear 425.

[0027] The drive assembly 43 drives the second gear 423 to rotate clockwise and counterclockwise. Through the synchronous transmission of a set of meshing second gears 423, the first spline shaft 421 and the second screw 422 rotate synchronously. The rotation of the second screw 422 generates axial thread thrust, which pushes the moving seat 424 to move smoothly to the left or right along the first spline shaft 421. The first spline shaft 421 synchronously drives the third gear 425 to rotate. The third gear 425 drives the first gear 45 and the first screw 44 to rotate, so that the first screw 44 rotates axially, driving the tap to complete the tapping and retraction actions.

[0028] The first screw 44 and the second screw 422 are designed to rotate in the same direction. When the moving seat 424 moves, the third gear 425 and the first gear 45 are always meshed, ensuring continuous and uninterrupted transmission and preventing tapping failure. The first spline shaft 421 not only provides guidance for the moving seat 424 but also drives the third gear 425 to rotate, taking into account both rotational power transmission and axial movement adaptation. It has a compact structure and high transmission efficiency.

[0029] Furthermore, the drive assembly 43 includes a frame 431 installed in the upper right corner of the inner cavity of the housing 41. A guide rod 432 is installed on the bottom inner side of the frame 431. A rack 433 that meshes with the second gear 423 is slidably connected to the outer wall of the guide rod 432. The outer wall of the guide rod 432 is rectangular, so that the rack 433 will not rotate when sliding along the guide rod 432. A pin 434 is installed in the middle of the upper surface of the rack 433. The pin 434 is cylindrical, so that the pin 434 slides more smoothly in the slide groove 4353. A rotating unit 435 is installed on the top inner side of the frame 431. The rack 433 is driven to move back and forth by the cooperation of the rotating unit 435 and the pin 434.

[0030] Furthermore, the rotating unit 435 includes a motor 4351 mounted on the front of the frame 431. One end of the rotating drum 4352 is mounted on the output end of the motor 4351. The other end of the rotating drum 4352 is connected to the inner wall of the frame 431 through a bearing. The rotating drum 4352 is hollow to reduce its weight and the load on the motor 4351 driving the rotating drum 4352 to rotate. The outer wall of the rotating drum 4352 is provided with a sliding groove 4353, and the pin 434 is inserted into the inner cavity of the sliding groove 4353. The sliding groove 4353 is elliptical and distributed on the outer wall of the rotating drum 4352. The two sides of the sliding groove 4353 are symmetrical with respect to the center line of the rotating drum 4352. If the curved surface of one side of the sliding groove 4353 presses the pin 434 forward, the curved surface of the other side presses the pin 434 backward. Therefore, the rack 433 moves back and forth.

[0031] Motor 4351 drives drum 4352 to rotate synchronously. During the rotation of drum 4352, elliptical symmetrical groove 4353 continuously generates radial thrust on pin 434, causing pin 434 to slide along groove 4353 and drive rack 433 to move back and forth in a linear motion along guide rod 432, providing stable reciprocating power to conveying assembly 42. The action switching of tapping and retraction can be completed without frequent forward and reverse rotation of motor.

[0032] The rack reciprocates by using the slide groove 4353 and the pin 434 to replace the electric control forward and reverse rotation, completely eliminating safety hazards such as poor heat dissipation, short circuits, and signal malfunctions, and is suitable for the complex working conditions of the foundry workshop with high dust and strong vibration.

[0033] The 4351 motor operates in one direction, eliminating frequent reversing impacts. The 4353 groove ensures smooth reciprocating motion without jamming, resulting in more precise tapping operations and adapting to the machining characteristics of castings with uneven hardness.

[0034] One rotation of the rotary drum 4352 completes one round trip of the rack 433. The power output cycle is fixed, and the tapping feed and retraction rhythm is stable and controllable.

[0035] Furthermore, the durability testing mechanism 5 includes a piston cylinder 51 installed at the left end of the first screw 44. The inner cavity of the piston cylinder 51 is filled with hydraulic oil 52. A second spline shaft 54 ​​and a piston 53 are sequentially inserted into the piston cylinder 51 from left to right. The second spline shaft 54 ​​is fixedly connected to the piston 53. The left end of the second spline shaft 54 ​​is installed at the right end of the chuck 6. The tap 7 transmits the tapping pressure to the second spline shaft 54, allowing the hydraulic oil 52 to sense the pressure change and converting the pressure change of the hydraulic oil 52 into the mechanical movement of the Bourdon tube 553. The piston 53 bears the pressure change when the tap 7 taps. A testing component 55 is installed on the outer wall of the piston cylinder 51.

[0036] Furthermore, the detection assembly 55 includes a housing 551 mounted on the outer wall of the piston cylinder 51. A through hole 552 is provided at the bottom front of the housing 551. A Bourdon tube 553 is mounted on the outer wall of the piston cylinder 51, and the Bourdon tube 553 is located within the inner cavity of the housing 551. The Bourdon tube 553 is arc-shaped and elastic; as the pressure of the hydraulic oil 52 gradually increases, the curvature of the Bourdon tube 553 decreases. A connecting rod 554 is mounted at the top of the Bourdon tube 553 via a pin. The inner cavity of the housing 551... A rocker arm 555 is mounted on the front side via a pin. The top of the rocker arm 555 is connected to the other end of the connecting rod 554 via a pin. The rocker arm 555 is pulled to the left or right by the Bourdon tube 553 and the connecting rod 554 in linkage. An adjustment unit 556 is installed at the bottom of the front of the box 551. The connection between the rocker arm 555 and the box 551 is located at the top of the rocker arm 555, which increases the swing distance at the bottom of the rocker arm 555, amplifies the pressure change, and facilitates the adjustment unit 556 to adjust the monitoring accuracy of the tap 7's durability.

[0037] The cutting resistance of tap 7 during tapping is transmitted to piston 53 via second spline shaft 54. Piston 53 squeezes hydraulic oil 52 in piston cylinder 51 to increase oil pressure. The oil pressure acts on arc-shaped Bourdon tube 553, causing it to undergo elastic deformation and reduce curvature. The deformation force pulls rocker arm 555 around the top hinge point through connecting rod 554. The bottom swing displacement of rocker arm 555 is amplified by lever and accurately triggers adjustment unit 556. When tap 7 wears and becomes dull, causing the cutting resistance to exceed the threshold, alarm 8 is immediately triggered to complete real-time monitoring of tap durability.

[0038] The rocker arm 555 is hinged at the top to form a lever amplification structure. Even a slight change in oil pressure can produce a noticeable swing. It can accurately identify slight wear of tap 7 and a small increase in cutting resistance, making it suitable for machining castings with large fluctuations in cutting load.

[0039] It achieves detection through hydraulic pressure transmission and mechanical linkage, eliminating electronic signal drift and electromagnetic interference issues. It is suitable for harsh working conditions such as dust and vibration in workshops, and has high detection reliability.

[0040] Changes in hydraulic pressure directly drive the deformation of the Bourdon tube 553, with no signal delay, and can reflect the cutting status and wear degree of the tap 7 in real time.

[0041] Furthermore, the adjustment unit 556 includes a slide bar 5561 installed at the bottom front of the housing 551. The curvature of the slide bar 5561 is consistent with the swing curvature of the swing arm 555, ensuring that the slide seat 5562 is adjusted along the movement direction of the swing arm 555. The slide seat 5562 is slidably connected to the outer wall of the slide bar 5561. A positioning bolt 5563 is screwed onto the lower surface of the slide seat 5562. When the positioning bolt 5563 is turned into contact with the slide bar 5561, the slide seat 5562 is fixed to the outer wall of the slide bar 5561. A proximity switch 5564 electrically connected to the alarm 8 is installed on the upper surface of the slide seat 5562. The position of the proximity switch 5564 is the trigger point of the swing arm 555, which can adjust the trigger pressure of the tap 7. It is suitable for tapping detection of castings of various materials and hardness.

[0042] Working principle: Step 1: Motor 4351 drives the rotating drum 4352 to rotate. The curved surface on one side of the slide groove 4353 presses the pin 434 forward, and the curved surface on the other side presses the pin 434 backward. During one rotation of the rotating drum 4352, the rack 433 completes one back-and-forth movement, providing power for tapping. Step 2: The rack 433 drives the second gear 423 to rotate clockwise and counterclockwise. Under the transmission of the two second gears 423, the first spline shaft 421 and the second screw 422 rotate synchronously. The rotational force of the second screw 422 drives the moving seat 424 to move left and right. While the third gear 425 moves with the moving seat 424, the first spline shaft 421 drives the third gear 425 to rotate. Under the transmission of the first gear 45 and the third gear 425, the first screw 44 moves left and right spirally along the housing 41. When the tap 7 moves to the left, it performs thread tapping on the casting held on the chuck 3. When the tap 7 moves to the right, it retracts the tool to achieve internal thread tapping on the casting. Step 3: During the tapping process, the cutting resistance generated by tap 7 acts on the second spline shaft 54. Piston 53 squeezes hydraulic oil 52. When the pressure of hydraulic oil 52 increases or decreases, Bourdon tube 553 deforms under the pressure of hydraulic oil 52, and the curvature decreases or increases. This causes connecting rod 554 to pull rocker arm 555 to the left or right, causing the bottom end of rocker arm 555 to swing to the right or left. Once rocker arm 555 corresponds to the position of proximity switch 5564, proximity switch 5564 is triggered due to obstruction, and alarm 8 sounds an alarm, indicating that the sharpness of tap 7 can no longer meet the tapping accuracy requirements of castings, and tap 7 needs to be replaced in time. Step four: When tapping castings of different materials and hardness, slide slide 5562 from left to right and use positioning bolt 5563 to lock and fix the moved slide 5562. The alarm trigger pressure of proximity switch 5564 gradually increases. Therefore, the durability detection threshold of tap 7 can be flexibly set according to the tapping requirements of different types of castings.

[0043] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these should also be considered within the scope of protection of the present invention. These will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A thread tapping device for machining castings, comprising a base (1), a hydraulic cylinder (2), and a chuck (3), wherein the hydraulic cylinder (2) is horizontally mounted on the top of the left side wall of the base (1), and the chuck (3) is mounted on the output end of the hydraulic cylinder (2). The chuck (3) locks the casting to be machined, and the hydraulic cylinder (2) drives the chuck (3) to move horizontally, so that the casting to be machined reaches the machining point. The device is characterized in that... A tapping mechanism (4) is installed on the upper right side of the base (1). A durability testing mechanism (5) is installed at the output end of the tapping mechanism (4). A chuck (6) is installed at the left end of the durability testing mechanism (5). A tap (7) is locked in the chuck (6). The tap (7) is driven by the tapping mechanism (4) to move left and right in a spiral motion to perform thread tapping on the casting. The durability testing mechanism (5) tests the working status of the tap (7) when it is tapping. An alarm (8) electrically connected to the durability testing mechanism (5) is installed on the upper surface of the tapping mechanism (4). The tapping mechanism (4) includes a housing (41) installed on the upper right side of the base (1). The upper and lower ends of the inner cavity of the housing (41) are respectively provided with a drive assembly (43) and a conveying assembly (42). The drive assembly (43) controls the operation of the conveying assembly (42). A first screw (44) is screwed to the top of the left side wall of the housing (41). A first gear (45) that meshes with the conveying assembly (42) is installed on the right end of the first screw (44). The conveying assembly (42) drives the first screw (44) to rotate back and forth, so that the first screw (44) moves left and right in a spiral motion to perform the tapping action (7).

2. The thread tapping device for machining castings according to claim 1, characterized in that, The conveying assembly (42) includes a first splined shaft (421) and a second screw (422) respectively mounted on the upper and lower ends of the right inner wall of the housing (41) via bearings. The right ends of both the first splined shaft (421) and the second screw (422) are equipped with meshing second gears (423). The first splined shaft (421) and the second screw (422) rotate synchronously via the two second gears (423). The outer wall of the second screw (422) is screwed with a movable... One end of the seat (424) and the other end of the movable seat (424) are sleeved on the outer wall of the first spline shaft (421). When the second screw (422) rotates clockwise or counterclockwise, the rotational force of the thread of the second screw (422) can drive the movable seat (424) to move to the left or right. A third gear (425) that meshes with the first gear (45) is installed on the top of the left side wall of the movable seat (424). The third gear (425) is driven to rotate by the first spline shaft (421).

3. The thread tapping device for machining castings according to claim 2, characterized in that, The first screw (44) and the second screw (422) have the same thread direction.

4. The thread tapping device for machining castings according to claim 3, characterized in that, The drive assembly (43) includes a frame (431) installed in the upper right corner of the inner cavity of the housing (41). A guide rod (432) is installed on the bottom inner side of the frame (431). A rack (433) that meshes with the second gear (423) is slidably connected to the outer wall of the guide rod (432). A pin (434) is installed in the middle of the upper surface of the rack (433). A rotating unit (435) is installed on the top inner side of the frame (431). The rack (433) is driven to move back and forth by the cooperation of the rotating unit (435) and the pin (434).

5. The thread tapping device for machining castings according to claim 4, characterized in that, The rotating unit (435) includes a motor (4351) installed on the front of the frame (431). One end of the output end of the motor (4351) is equipped with a rotating drum (4352). The other end of the rotating drum (4352) is connected to the inner wall of the frame (431) through a bearing. The outer wall of the rotating drum (4352) is provided with a sliding groove (4353), and a pin (434) is inserted into the inner cavity of the sliding groove (4353).

6. The thread tapping device for machining castings according to claim 5, characterized in that, The grooves (4353) are elliptical in shape and distributed on the outer wall of the rotating cylinder (4352).

7. The thread tapping device for machining castings according to claim 6, characterized in that, The durability testing mechanism (5) includes a piston cylinder (51) installed at the left end of the first screw (44). The inner cavity of the piston cylinder (51) is filled with hydraulic oil (52). The piston cylinder (51) is connected to a second spline shaft (54) and a piston (53) from left to right. The second spline shaft (54) is fixedly connected to the piston (53). The left end of the second spline shaft (54) is installed at the right end of the chuck (6). The piston (53) is subjected to pressure changes when the tap (7) taps. The outer wall of the piston cylinder (51) is equipped with a testing component (55).

8. The thread tapping device for machining castings according to claim 7, characterized in that, The detection component (55) includes a box (551) installed on the outer wall of the piston cylinder (51). The bottom front of the box (551) has a through hole (552). A Bourdon tube (553) is installed on the outer wall of the piston cylinder (51) and is located in the inner cavity of the box (551). The Bourdon tube (553) is arc-shaped and elastic. As the pressure of the hydraulic oil (52) gradually increases, the curvature of the Bourdon tube (553) decreases. A connecting rod (554) is installed at the top of the Bourdon tube (553) through a pin. A rocker arm (555) is installed on the front side of the inner cavity of the box (551) through a pin. The top of the rocker arm (555) is connected to the other end of the connecting rod (554) through a pin. An adjustment unit (556) is installed at the bottom front of the box (551).

9. The thread tapping device for machining castings according to claim 8, characterized in that, The connection between the swing rod (555) and the box (551) is located at the top of the swing rod (555).

10. The thread tapping device for machining castings according to claim 9, characterized in that, The adjustment unit (556) includes a slide bar (5561) installed on the bottom front of the box (551). A slide block (5562) is slidably connected to the outer wall of the slide bar (5561). A positioning bolt (5563) is screwed onto the lower surface of the slide block (5562). When the positioning bolt (5563) is turned and contacts the slide bar (5561), the slide block (5562) is fixed to the outer wall of the slide bar (5561). A proximity switch (5564) electrically connected to the alarm (8) is installed on the upper surface of the slide block (5562).

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